This Application seeks renewal of the Center for AIDS Research (CFAR) at the University of Massachusetts Medical School (UMASS) initially established in September of 1998. The CFAR provides the organizational framework to enhance and coordinate AIDS-related research at the Institution. The Developmental Core (Core B) provides new investigator support, as well as promoting the initiation of collaborative and translational research projects. Basic research and translational research are coordinated and supported by Clinical, Molecular Virology , Molecular Biology, and Animal Models (Core F) cores. The CFAR enhances other established programs at the Institution including AIDS Clinical Trials groups as well as NIAID-funded doctoral and post-doctoral training programs in Immunology and Virology. The CFAR is directed by Mario Stevenson, Ph.D., with Ronald Desrosiers, Ph.D. and John Sullivan, M.D. serving as CFAR Co-Directors. Through the advice of Internal and External Advisory committees, the CFAR keeps pace with the changing needs of AIDS researchers at the Institution.